Supported Metal Oxide Catalysts Research Articles

Strong Metal-Support Interaction between Pt and TiO2 over High-temperature CO2 Hydrogenation.

The catalytic activities and stability of oxide-supported metal catalysts are significantly affected by metal-support interactions (MSI) between oxidic supports and supported metals. The surface properties of the support, such as its phase and defects, are crucial in MSI, including both the strong metal-support interaction (SMSI) and electronic metal-support interaction (EMSI). In this study, modulation of SMSI was achieved on rutile-supported Pt nanoparticles (NP) over high-temperature CO2 hydrogenation. The encapsulation of Pt NP surfaces with TiO2-x overlayers is precisely controlled by the defects. It is found that oxygen vacancy defects significantly enhance the catalytic stability of Pt/rutile under high-temperature reverse water-gas shift (RWGS) reaction by inhibiting the occurrence of SMSI. Pt/rutile with oxygen vacancies achieves a 301 molCO×gM-1×h-1 space time yield and considerably catalytic stability (decreased by 8%) at 800 °C over 100 h time-on-stream. Density functional theory (DFT) calculations suggest that the adsorption capacity of Pt NP on the rutile overlayer can be reduced by increasing electron density. Experimental results combined with DFT calculations show that electron transfer from Pt NP to rutile is reduced by the oxygen vacancy defects on Pt/R, preserving the metallic nature of Pt species during CO2 hydrogenation, thereby preventing the formation of SMSI.

Metal Supported Metal Oxide Catalysts for Hydrogen Peroxide Production Via Water Splitting

The two-electron water oxidation reaction (WOR) has drawn recent attention as an efficient, simple method of producing on-site hydrogen peroxide through electrochemical water splitting. However, finding electrocatalysts with high activity and stability in the reaction’s harsh oxidizing environment is challenging. This is made especially difficult due to the competing four-electron and one-electron WOR, which necessitate a catalyst material with high selectivity towards the hydrogen peroxide production pathway. Here, we utilize metal/metal oxide coupling interactions to tune metal oxide catalysts to be active for 2 e- WOR via the creation of a Mott-Schottky junction. Metal/metal oxide interactions have been well studied for supported metal catalysts, but their behavior has been less investigated for catalysts where the metal oxide provides the active sites, called inverse catalysts. In this case, the difference in work functions between the metal support and metal oxide semiconductor catalyst drives electron transfer between the two, facilitating electronic interactions which can modulate the binding energy of reaction intermediates at the interface and thus tune the catalytic ability of the metal oxide. In this work, we investigate a variety of metal oxide catalyst and metal support materials and find that a thin layer of indium tin oxide (ITO) supported by a layer of platinum (Pt) has excellent catalytic ability towards 2 e- WOR. The activity, selectivity, and stability of the ITO/Pt catalyst shows significant improvement over the unsupported ITO catalyst and yields hydrogen peroxide production rates greater than those reported in literature using other standard catalysts for this reaction. This method of catalyst engineering also provides a future pathway to create new catalysts for this electrochemical reaction. Figure 1

The Conundrum of "Pair Sites" in Langmuir-Hinshelwood Reaction Kinetics in Heterogeneous Catalysis.

Understanding reaction kinetics is crucial for designing and applying heterogeneous catalytic processes in chemical and energy conversion. Here, we revisit the Langmuir-Hinshelwood (L-H) kinetic model for bimolecular surface reactions, originally formulated for metal catalysts, assuming immobile adsorbates on neighboring pair sites, with the rate varying linearly with the density of surface sites (sites per unit area); r ∝ [*]o 1. Supported metal oxide catalysts, however, offer systematic control over [*]o through variation of the active two-dimensional metal oxide loading in the submonolayer region. Various reactions catalyzed by supported metal oxides are analyzed, such as supported VO x catalysts, including methanol oxidation, oxidative dehydrogenation of propane and ethane, SO2 oxidation to SO3, propene oxidation to acrolein, n-butane oxidation to maleic anhydride, and selective catalytic reduction of nitric oxide with ammonia. The analysis reveals diverse dependencies of reaction rate on [*]o for these surface reactions, with r ∝ [*]o n , where n equals 1 for reactions with a unimolecular rate-determining step and 2 for those with a bimolecular rate-limiting step or exchange of more than 2 electrons. We propose refraining from a priori assumptions about the nature and density of surface sites or adsorbate behavior, advocating instead for data-driven elucidation of kinetics based on the density of surface sites, adsorbate coverage, etc. Additionally, recent studies on catalytic surface mechanisms have shed light on nonadjacent catalytic sites catalyzing surface reactions in contrast to the traditional requirement of adjacent/pair sites. These findings underscore the need for a more nuanced approach in modeling heterogeneous catalysis, especially supported metal oxide catalysts, encouraging reliance on experimental data over idealized assumptions that are often difficult to justify.

Synergy and site dependent kinetics of photo-thermal catalysis over Pt/TiO2 for methanol decomposition

Photo-thermal catalysis which interplay the heat and light-induced effects have drawn broad attention owing to their synergistic effect to extend the capability of chemical transformation. Here, the effect of heat and/or light on methanol decomposition has been clarified. On Pt/TiO2, light irradiation activates the TiO2 and enhance the absorption and the oxidation of intermediates. The main intermediate under PTC condition is formaldehyde, which is the same to TC condition rather than methyl formate under PC condition. Differences CO absorption site correlates with the key intermediates under PC and TC/PTC conditions. Light and heat display their strengths in a synergistic manner, optimizing the activity to promote efficient catalytic processes which is verified to be photo-assisted thermal catalysis. This work offers detailed mechanistic understanding of the surface species and paves the way for an educated microkinetic modeling approach under photo and/or thermal condition over oxide-supported metal catalysts.

Boosting catalytic oxidation of propane over CeO2-supported Co3O4 catalyst with strong interfacial interaction and electron transfer

Tuning the nanoparticle-support interaction can optimize the catalytic performance of supported metal oxide catalysts for VOCs removal. Herein, a series of Co3O4/CeO2 catalysts with different strengths of interfacial interaction and electron transfer were successfully constructed via various modified wetness impregnation procedures. With the introduction of ammonium hydroxide, citric acid or H2 pretreatment, a stronger interfacial interaction and electron transfer were achieved due to the highly Co3O4 dispersion and CeO2 surface reconstruction. The modified-synthesis Co3O4/CeO2 catalysts, particularly Co3O4/CeO2-CA (citric acid), demonstrated superior catalytic activity (T90 = 296 °C, TOF = 0.337 × 10−3 s−1) and stability for propane oxidation as compared to typical wetness impregnation Co3O4/CeO2-DI (T90 = 314 °C, TOF = 0.121 × 10−3 s−1). Through systematic characterizations and DFT calculation, the strong interfacial interaction and abundant reactive oxygen species facilitate the adsorption and activation of C3H8 and O2 on the catalyst surface, which further promote the intermediates (carbonate/carboxyl species) transformation. These findings highlight interfacial mechanism to catalytic performance optimization of supported metal oxides.

Enhanced CO2 methanation activity of Ni-Rutile-based catalyst by tuning the metal−support interaction with Fe doping

CO2 methanation is an effective way for CO2 recycling, and nickel-based catalysts have attracted much attention in this field due to their excellent CH4 selectivity and cost-effectiveness; however, their applications are limited by their suboptimal catalytic activity. In this work, the catalytic activity of Ni-rutile-based catalysts was increased by almost an order of magnitude simply by doping the rutile with Fe. Series characterizations show that three factors that mainly contributed to the improved catalytic performance of the Ni/Fe-Rutile, which are the reduction of the Ni size, the increase of the basic sites, and the inhibition of the encapsulation of the Ni particles by the support. With Fe doping, the OH and oxygen vacancies on the rutile surface were reduced, which made the support difficult to reduce and thus suppressed the encapsulation of Ni by the support. As a result, the number of exposed active sites on the Ni/Fe-Rutile which with a smaller Ni size was further successfully increased, and the catalytic activity was significantly improved. This study provides new ideas for the design of activity-enhanced supported catalysts from the perspective of tuning the metal-support interaction and may be applicable to other reducible oxide-supported metal catalysts.

Review on advancements of pyranopyrazole: synthetic routes and their medicinal applications.

Pyranopyrazoles are among the most distinguished, biologically potent, and exciting scaffolds in medicinal chemistry and drug discovery. Synthesis and design of pyranopyrazoles using functional modifications via multicomponent reactions (MCRs) are thoroughly found in synthetic protocols by forming new C-C, C-N, and C-O bonds. This review aims to focus on the biological importance of pyranopyrazoles as well as on a diverse synthetic approach for their synthesis using various catalytic systems such as acid-catalyzed, base-catalyzed, ionic liquids and green media-catalyzed, nano-particle-catalyzed, metal oxide-supported catalysts, and silica-supported catalysts. In this review, we have summarized data on the advancements in synthesizing pyranopyrazole from the last two decades to the mid-2023 and research papers describing the importance of these scaffolds. This review will be significant for synthetic organic chemists and researchers working in organic chemistry.

External [1 1 1] facets on nanorod gamma alumina boosts catalytic reductive amination of carbonyl compound to primary amine

Hydrogen spillover had played a significant role in catalytic processes involving reducible oxide supported metal catalyst and hydrogen molecule. Herein, crystal plane regulative hydrogen spillover strategy for the effective reductive amination on Ni/Al2O3 was developed. A rod-like alumina supported Ni catalyst with primarily external (111) facets was prepared. In the presence of NH3 and H2, Ni/Al2O3 (111) exhibited a turnover number of 30.4 h−1, which was 136-fold higher than that of Ni/Al2O3 (110) in the reductive amination of furfural to furfuryl amine. For the Ni/Al2O3 (111) catalyst, Al2O3 (111) facets exhibited strong Lewis acidity, resulting in an enhanced H affinity of Al2O3 (111) and a positively charged of Ni through electronic interaction. It was revealed that strong H affinity of Al2O3 (111) and positively charged Ni sites significantly promoted hydrogen migration from Ni surface to Al2O3 (111) facets, which effectively prevented the Ni sites from hydrogen poisoning and enhanced the adsorption and activation of NH3 and intermediates for reductive amination. Consequently, the activation energy of Schiff base reductive ammonolysis was obviously reduced, resulting in high inherent activity for furfural reductive amination to furfuryl amine. This work developed a new strategy for high efficiency reductive amination catalyst in terms of hydrogen spillover effect.

Impact of Calcination Temperature on Tungsten‐based Composite Catalysts for Olefins Metathesis

AbstractThe thermal treatment is one of the key procedures for the distribution and transformation of active sites for the supported metal oxide catalysts. However, the underlying impacts of thermal treatment on composite supported catalysts receives limited attention due to the additional complexity of the composite support. In this work, the progressive gradient in the metathesis activity, as the function of enhanced calcination temperature, has been observed for the tungsten‐based catalysts supported on the hierarchical ZSM‐5 zeolite‐alumina composite. The metathesis activity, reflected by ethene conversion, undergoes a stepwise growth from 24.2 % to 38.9 % along with the enhanced calcination temperature from 723 K to 923 K. The supported W‐oxo species share high similarity in structural states except their interaction with the Brønsted acidic bridge hydroxyl groups in zeolite. The density of bridge hydroxyl groups is reduced as the function of enhanced calcination temperatures, which reflects the intensified anchoring of surface W‐oxo species. It should be noted that such dependence is not observed for their counterparts based on microporous ZSM‐5 zeolite‐alumina. These sharp comparisons highlight the critical routes of thermal migration of W‐oxo species along the intrazeolite‐alumina interface in the evolution of active sites for the olefins cross‐metathesis reaction.

Diving into the interface-mediated Mars-van Krevelen (M−vK) characteristic of CuOx-supported CeO2 catalysts

The unique interface synergistic catalytic properties for metal oxide-supported catalysts have long been explored in several critical heterogeneous catalytic processes (e.g., CO oxidation reactions). However, interfacial synergistic catalysis is still a hitherto undescribed mechanism due to the lack of direct evidence at the atomic level. Thereinto, the CuOx-supported CeO2 (CuOx/CeO2) catalyst is a typical case. Herein, a combination study including representative theoretical calculations, in situ DRIFTS spectra and tailored molecular probe experiments supports a new carbonate-interface mediated Mars-van Krevelen (M−vK) mechanism for CO oxidation, i.e., CO molecules form carbonate intermediate species directly between spatial proximity (2.99 Å) double lattice oxygen sites with low oxygen vacancies formation energy (EformOv = 0.82 eV/0.83 eV) at the copper−ceria interface. The reaction energy barrier of this process is 0.32 eV, much lower than the 1.23 eV of the conventional M−vK mechanism. Besides, the spatial effect of double oxygen vacancies (Ov) generated by the depletion of intermediate carbonate species promotes the sustained and dynamic activation of O2, hence facilitating the efficient operation of the M−vK mechanism at low temperatures.

Rational design of vanadia-based propane ODH catalysts: A multiple operando spectroscopic investigation of VOx/TiO2/CeO2

The understanding of reaction mechanisms of supported metal oxide catalysts has significantly increased over the last years due to new methods being applied. This increased knowledge allows to develop approaches towards catalytic materials for reactions with low selectivities by rational design, such as the oxidative dehydrogenation (ODH) of propane, which is of great technical importance. Vanadia (VOx) supported on reducible oxides (TiO2, CeO2, etc.) has shown promising catalytic properties in propane ODH. In this study, we followed a rational-design approach employing atomic layer deposition (ALD) to synthesize a VOx/TiOx/CeO2 catalyst with superior selectivity, by combining favourable properties of the individual catalysts (VOx/TiO2, VOx/CeO2). By applying multiple spectroscopies, including multi-wavelength Raman, UV-Vis, DRIFT, and XP spectroscopy as well as XRD, we were able to identify the functions of each oxide and develop a mechanistic picture. The increased selectivity is the result of distinct interactions between the oxides that slow down the oxygen dynamics in the catalyst and favour reaction pathways beneficial to propylene formation. Our findings highlight the use of rational design to develop improved catalysts based on previously established mechanistic knowledge.

A Green Approach to Obtaining Glycerol Carbonate by Urea Glycerolysis Using Carbon-Supported Metal Oxide Catalysts.

The results of sustainable and selective synthesis of glycerol carbonate (GC) from urea and glycerol under ambient pressure using carbon-fiber-supported metal oxide catalysts are reported. Carbon fibers (CF) were prepared via a catalytic chemical vapor deposition method (CCVD) using Ni as a catalyst and liquefied petroleum gas (LPG) as a cheap carbon source. Supported metal oxide catalysts were obtained by an incipient wetness impregnation technique using Zn, Ba, Cr, and Mg nitrates. Finally, the samples were pyrolyzed and oxidized in an air flow. The obtained catalysts (10%MexOy/CFox) were tested in the reaction of urea glycerolysis at 140 °C for 6 h under atmospheric pressure, using an equimolar ratio of reagents and an inert gas flow for NH3 removal. Under the applied conditions, all of the prepared catalysts increased the glycerol conversion and glycerol carbonate yield compared to the blank test, and the best catalytic performance was shown by the CFox-supported ZnO and MgO systems. Screening of the reaction conditions was carried out by applying ZnO/CFox as a catalyst and considering the effect of reaction temperature, molar ratio of reagents, and the mode of the inert gas flow through the reactor on the catalytic process. Finally, a maximum yield of GC of about 40%, together with a selectivity to glycerol carbonate of ~100%, was obtained within 6 h of reaction at 140 °C using a glycerol-to-urea molar ratio of 1:1 while flowing Ar through the reaction mixture. Furthermore, a positive heterogeneous catalytic effect of the CFox support on the process was noticed.

Revisiting dispersion and reactivity of active sites via a restricted random distribution model over supported vanadia catalysts for NO reduction

The structure and dispersion of active sites substantially impact the performance of supported metal oxide catalysts, as exemplified by the V2O5/TiO2 catalysts used for NH3-SCR reaction. Due to the complexity of the active site dispersion on the catalyst surface, the intrinsic law of this structure–activity relationship remains controversial. Herein, we proposed a restricted random distribution model to describe the stochastic anchoring behavior of active sites on the TiO2 surface during the loading process of vanadia. The structures of monomeric, dimeric, and polymeric VOx sites were determined by DFT calculations and verified with spectroscopy and adsorption information experimentally. The calculated reaction pathways and energy profiles for these structures indicated that the dual sites configuration and terminal V(=O)2 bond are responsible for the high reactivity of aggregated VOx sites. Combining the reactivity of these various sites and the random distribution method, we built a general profile of the correlation between the V2O5/TiO2 catalyst surface and its reaction performance. The reactivity results obtained from experimental in situ DRIFTS and kinetic tests validate our theoretical model. The random distribution method links DFT calculations and experiments, coupling the structure and dispersion of the VOx active sites to the catalyst reactivity.

Dynamic Behavior of Intermediate Adsorbates to Control Activity and Product Selectivity in Heterogeneous Catalysis: Methanol Decomposition on Pt/TiO2(110).

Dynamic behavior of intermediate adsorbates, such as diffusion, spillover, and reverse spillover, has a strong influence on the catalytic performance in oxide-supported metal catalysts. However, it is challenging to elucidate how the intermediate adsorbates move on the catalyst surface and find active sites to give the corresponding products. In this study, the effect of the dynamic behavior of methoxy intermediate on methanol decomposition on a Pt/TiO2(110) surface has been clarified by combination of scanning tunneling microscopy (STM), temperature-programmed desorption (TPD), and density functional theory (DFT) calculations. The methoxy intermediates were formed by the dissociative adsorption of methanol molecules on Pt nanoparticles at room temperature followed by spillover to the TiO2(110) support surface. TPD results showed that the methoxy intermediates were thermally decomposed at >350 K on the Pt sites to produce CO (dehydrogenation) and CH4 (C-O bond scission). A decrease of the Pt nanoparticle density lowered the activity for the decomposition reaction and increased the selectivity toward CH4, which indicates that the reaction is controlled by diffusion and reverse spillover of the methoxy intermediates. Time-lapse STM imaging and DFT calculations revealed that the methoxy intermediates migrate on the five-fold coordinated Ti (Ti5c) sites along the [001] or direction with the aid of hydrogen adatoms bonded to the bridging oxygens (Obr) and can move over the entire surface to seek and find active Pt sites. This work offers an in-depth understanding of the important role of intermediate adsorbate migration in the control of the catalytic performance in oxide-supported metal catalysts.

Elucidating the Structure and Composition of Individual Bimetallic Nanoparticles in Supported Catalysts by Atom Probe Tomography.

Understanding and controlling the structure and composition of nanoparticles in supported metal catalysts are crucial to improve chemical processes. For this, atom probe tomography (APT) is a unique tool, as it allows for spatially resolved three-dimensional chemical imaging of materials with sub-nanometer resolution. However, thus far APT has not been applied for mesoporous oxide-supported metal catalyst materials, due to the size and number of pores resulting in sample fracture during experiments. To overcome these issues, we developed a high-pressure resin impregnation strategy and showcased the applicability to high-porous supported Pd-Ni-based catalyst materials, which are active in CO2 hydrogenation. Within the reconstructed volume of 3 × 105 nm3, we identified over 400 Pd-Ni clusters, with compositions ranging from 0 to 16 atom % Pd and a size distribution of 2.6 ± 1.6 nm. These results illustrate that APT is capable of quantitatively assessing the size, composition, and metal distribution for a large number of nanoparticles at the sub-nm scale in industrial catalysts. Furthermore, we showcase that metal segregation occurred predominately between nanoparticles, shedding light on the mechanism of metal segregation. We envision that the presented methodology expands the capabilities of APT to investigate porous functional nanomaterials, including but not limited to solid catalysts.

Niobium-doped conductive TiO-TiO2 heterostructure supported bifunctional catalyst for efficient and stable zinc-air batteries

The development of highly active and durable nonprecious metal-based bifunctional electrocatalysts for oxygen reduction/evolution reaction (ORR/OER) is important for rechargeable zinc-air batteries. Herein, a three-dimensional conductive niobium-doped TiO-TiO2 heterostructure supported ZIF-67-derived Co-NC bifunctional catalyst was fabricated. In the Co-NC@Nb-TiOx catalyst, the Nb doping promoted the formation of TiO-TiO2 heterojunction support, enhanced its conductivity and stability and provided strong electron metal-support interaction between Co-NC and Nb-TiOx. Also, the supported Co-NC nanoparticles provided abundant active sites with excellent ORR/OER activity. Experimental analysis reveals that the high OER activity of Co-NC@Nb-TiOx can be attributed to the in-situ generated CoOOH species. It exhibits excellent ORR activity, as shown by its onset potential (0.95 V vs. RHE) and half-wave potential (0.86 V vs. RHE). Its OER overpotential at 10 mA cm−2 is 480 mV. The zinc-air battery realizes outstanding cycling stability over 225 h cycles tested at 10 mA cm−2. This work demonstrates the importance of designing highly stable metal oxide-supported catalysts in electrochemical energy conversion devices.

Oxide-supported metal catalysts for anaerobic NAD+ regeneration with concurrent hydrogen production

We report SiO2-supported monometallic Pt, Pd, Au, Ni, Cu and Co catalysts for proton-driven NAD+ regeneration, co-producing H2. All metals are fully selective to NAD+ where the order of turnover frequencies (Pt > Pd > Cu > Au, Ni and Co) coincides with those otherwise observed in electrochemical hydrogen evolution reactions. This has revealed that NADH is capable of converting the metal sites into a “cathode” without an external potential and the NADH to NAD+ reaction involves transferring electron and hydrogen atom separately. Electron-deficient Ptδ+ (on CeO2) enhances TOF and the heterogeneous Pt/CeO2 catalyst is recyclable without losing any activity/selectivity.

Mild and selective catalytic oxidation of 5-HMF to 2,5-FDCA over metal loaded biomass derived graphene oxide using hydrogen peroxide in aqueous media

Biomass-derived graphene oxide-supported metal catalysts (Ru@S-GO, Pd@ S-GO, and Pd/Ru@ S-GO) were produced in a tube furnace with a metal loading of 1 weight percent. All the synthesised nano catalysts were well characterised by XRD, FESEM-EDS, ICP-OES, XPS and FTIR, and applied for the oxidation of 5-hydroxymethylfurfural (5-HMF) to 2,5-furan dicarboxylic acid (FDCA). Hydrogen peroxide was utilized as the liquid oxidant due to its reduced mass transfer resistance. 5-HMF used in this study was also obtained from biomass. All the operational parameters, such as temperature of the reaction, amount of oxidant, base concentration, and catalyst loading were optimized using Response surface methodology (RSM) based on central composite design (CCD). Ru@S-GO was found to have greater activity and selectivity towards FDCA under benign reaction conditions, and complete conversion of 5-HMF to 2,5-FDCA was accomplished (98.8% yield) over 5 hours of reaction time in an aqueous medium with a lower catalyst loading and reduced metal content.

Metal Oxide-Supported Metal Catalysts for Electrocatalytic Oxygen Reduction Reaction: Characterization Methods, Modulation Strategies, and Recent Progress.

The sluggish kinetics of the oxygen reduction reaction (ORR) with complex multielectron transfer steps significantly limits the large-scale application of electrochemical energy devices, including metal-air batteries and fuel cells. Recent years witnessed the development of metal oxide-supported metal catalysts (MOSMCs), covering single atoms, clusters, and nanoparticles. As alternatives to conventional carbon-dispersed metal catalysts, MOSMCs are gaining increasing interest due to their unique electronic configuration and potentially high corrosion resistance. By engineering the metal oxide substrate, supported metal, and their interactions, MOSMCs can be facilely modulated. Significant progress has been made in advancing MOSMCs for ORR, and their further development warrants advanced characterization methods to better understand MOSMCs and precise modulation strategies to boost their functionalities. In this regard, a comprehensive review of MOSMCs for ORR is still lacking despite this fast-developing field. To eliminate this gap, advanced characterization methods are introduced for clarifying MOSMCs experimentally and theoretically, discuss critical methods of boosting their intrinsic activities and number of active sites, and systematically overview the status of MOSMCs based on different metal oxide substrates for ORR. By conveying methods, research status, critical challenges, and perspectives, this review will rationally promote the design of MOSMCs for electrochemical energy devices.

Emission Control of Toluene in Iron Ore Sintering Using Catalytic Oxidation Technology: A Critical Review

Iron ore sintering flue gas containing large amounts of volatile organic compounds (VOCs) can form secondary photochemical smog and organic aerosols, thus posing a serious threat to human health and the ecological environment. Catalytic combustion technology has been considered as one of the most prospective strategies for VOC elimination. This paper focuses on a review of studies on catalytic removal of typical VOCs (toluene) on transition metal oxide catalysts in recent years, with advances in single metal oxides, multi-oxide composites, and supported metal oxide catalysts. Firstly, the catalytic activities of a series of catalysts for toluene degradation are evaluated and compared, leading to an analysis of the key catalytic indicators that significantly affect the efficiency of toluene degradation. Secondly, the reaction pathway and mechanism of toluene degradation are systematically introduced. Considering the site space and investment cost, the conversion of VOC pollutants to harmless substances using existing selective catalytic reduction (SCR) systems has been studied with considerable effort. Based on the current development of simultaneous multi-pollutant elimination technology, the interaction mechanism between the NH3-SCR reaction and toluene catalytic oxidation on the surface is discussed in detail. Finally, views on the key scientific issues and the challenges faced, as well as an outlook for the future, are presented. This overview is expected to provide a guide for the design and industrial application of NO/VOC simultaneous removal catalysts.